Prior art workers have devised many types of portable pitching mounds. For the most part, the prior art portable pitching mounds comprise a moulded fiberglass shell in part, at least, covered with a resilient material, an artificial turf material, or the like. Examples of such mounds are taught in U.S. Pat. Nos. 4,306,718 and 4,749,223. U.S. Pat. No. 3,703,285 teaches a pitchers mound made of plastic material having integral supporting ribs. The bottom surfaces of the mound are provided with a non-skid pad adhesively affixed thereto. U.S. Pat. No. 4,925,186 teaches a portable pitchers mound comprising a plurality of parts. U.S. Pat. No. 3,236,520 teaches a portable baseball training mound, the body of which can be made of foamed plastic, fiberglass, or in the form of a metal shell. The mound is provided with a front shield of rubber or plastic.
The present invention is based upon the discovery that if a portable pitching mound is made with an expanded plastic core, the exposed surfaces (top surfaces and peripheral edge surfaces) of which are covered with a flexible, sheet-like, artificial turf material, the resulting mound is very durable, extremely lightweight, and gives the user the feel of an earth mound. This construction can be used to make a one-piece ramp-like practice mound, or a multi-piece full size mound, as will be described hereinafter. The portable mounds of the present invention are significantly lighter in weight than the prior art mounds and do not require folding or the provision of casters, or the like to assist in transporting the mound. As a result, the mounds of the present invention are easy to store and easy to set up.
By virtue of their construction, the mounds of the present invention are essentially maintenance free and weather proof. The mounds demonstrate limited compression of the surface with nearly a full recovery to the original shape. The mounds can even withstand the use of spiked shoes.